Is this about loading tabs when you start Firefox or when Firefox is running and you go to another tab ?

Firefox will detect if your computer's memory is running low, which is defined as lower than 400MB, and suspend unused tabs that you haven't used or looked at in a while. The new tab unload feature is controlled on the about:config page with a preference that you can set to false to disable this feature. Keep in mind that this makes you vulnerable to low memory issues.

• browser.tabs.unloadOnLowMemory = false

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

• http://www.ghacks.net/2019/03/01/firefox-67-automatically-unload-unused-tabs-to-improve-memory/

Thanks for responding. This is occurring when the browser is open and running. I have done all of the suggested config options. Restarted and it’s still refreshing after 10 seconds of leaving one tab for another. Not sure if it’s a setting in my Mac or not beyond Firefox

Your System Details show the Total Suspender extension that is probably causing this.

• https://addons.mozilla.org/firefox/addon/total-suspender/

A minimalistic web extension for firefox that suspends natively (with tabs.discard) all non-active tabs and requires only minimal permissions to store it's settings and filter URL's.

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Thanks cor-el that fixed the problem! It was still active on my old machine with no problems so that was interesting to find. Thanks for your help